Histamine-evoked nasal secretion in the dog

Area of Science:

• Pharmacology
• Physiology
• Veterinary Medicine

Background:

• Nasal secretions play a crucial role in respiratory health.
• Understanding the regulation of nasal secretory activity is important for treating various conditions.

Purpose of the Study:

• To investigate the mechanisms underlying nasal secretory activity in dogs.
• To determine the specific roles of histamine and methacholine in stimulating nasal secretions.

Main Methods:

• Nasal secretory activity was measured in seven dogs.
• Topical stimulation using histamine and methacholine was performed.
• The effects of atropine and chlorpheniramine on these responses were evaluated.

Main Results:

• Methacholine-induced nasal secretion was inhibited by atropine.
• Histamine-induced nasal secretion was inhibited by chlorpheniramine.
• Neither blocker affected the response to the other stimulant.

Conclusions:

• The findings suggest two independent mechanisms regulate canine nasal secretion.
• One pathway involves muscarinic receptors (methacholine-sensitive) and the other involves histamine receptors.
• This provides insight into the complex control of nasal fluid production.